Common issues
This article collects the issues that come up most often while building a flow in the Flow Builder, each with its cause and its fix.
A flow won’t preview or publish
You can’t publish or preview your flow if any of the following issues are present.
- An interaction with an incomplete configuration. Common cases:
- An Open URL action without a target URL.
- A Navigate to screen action without a destination — also occurs when the destination screen is deleted after the action is set up.
- A conditional action without an operator or value.
- A Set variable action without a variable/value assignment.
- A Purchase action with no product (in-app store) or no Web Paywall URL (web payment).
- A Custom action without an Action ID.
- A Show alert action with an empty Title or Message.
- A Show or Hide action with no element selected.
- A Select product action with no target product — also occurs when the target product element is deleted, moved out of its product group, or left on another screen.
- A Select product action saved inside a reusable component, or one that targets an element ID used on more than one screen.
- A screen with no elements.
- A product element without a product attached — may occur if you remove the referenced product.
- An invalid remote config JSON breaks the entire delivery process — you cannot even save the draft.
To catch these before publishing, preview the flow in the Adapty app. If the flow fails to load there, the error message gives you more detail.
A Set variable action doesn’t change the selected product
Which product is selected isn’t a variable you can assign, so Set variable can’t move the selection. Use the Select product action instead.
An image or video won’t upload
A file outside the Flow Builder’s media limits won’t upload. Verify the file against the Image and Video requirements:
| Element | Formats | Maximum file size | Other limits |
|---|---|---|---|
| Image | .JPG, .PNG, .WEBP | 20 MB | — |
| Video | .MP4, .WEBM | 50 MB | 30 seconds maximum; 640×640 pixels minimum |
These formats aren’t supported:
- Animated GIFs and animated WEBPs: To add motion, use a Video element instead.
- SVG: Export the file as PNG or WEBP. For icons, you don’t upload anything — the Icon element draws from the bundled Tabler Icons library.